The present invention relates to vane assemblies suitable for use in fluid pumps, and more particularly to static vane assemblies for producing radial loads on turbopump components.
Rocket engines can utilize turbopumps to deliver propellants to an injector assembly in the combustion chamber. Such turbopumps have rotors that rotate as the turbopump operates, and impellers that rotate as part of the rotor to increase the pressure of propellants or propellant mixtures. It is desired to obtain a low, steady synchronous vibration response during turbopump operation. However, for a variety of reasons, a particular turbopump may produce an undesired sub-synchronous response. Sub-synchronous vibration responses can be caused, at least in part, by insufficient radial loading on a given bearing set of the turbopump.
Undesired asynchronous vibration response issues could be addressed in a number of ways. However, many potential solutions are overly complex, insufficiently robust, or are otherwise undesirable, for instance, resulting in an unsatisfactory turbopump performance loss. As one example, the rotor bearings could be redesigned, but redesigns of rotor bearings are difficult and complex. Moreover, flow inlets and outlets create load vectors that could be optimized relative to undesired vibrations, but optimal inlet and outlet flow paths may undesirably increase engine size and/or mass and may provide optimal design “windows” (i.e., tolerances on desired vibration characteristics) that are too small to be practical.